Dropping in on the exclusive, members-only sport, trailing tankers and riding the waves.

James Fulbright, along with brothers Doug and Joe Mims, is zipping through Galveston Bay in a 23-foot powerboat, stalking a massive wave. The churning, white-capped swell—nearly two miles long and four feet high—trails behind a hulking Greek oil tanker, the Astro Sculptor.

Navigating waters nearly 50 feet deep, surrounded by barges, fishing boats, seagulls and albatross, the men have been chasing the tanker all morning, waiting for it to pick up speed. A computer affixed to Joe’s boat—running software that names and tracks tankers’ speed and paths—shows the Sculptor hitting 14 miles per hour. “Look at that monster,” whoops James, a slender, tanned fifty-something with sun-bleached locks. “That’s a beauty—let’s get in there!”

James and Doug drop their 12-foot longboards into the water and paddle furiously toward the wave. “I’ll give you five bucks if you knock Doug off his board,” Joe yells from the boat, ribbing his lookalike brother, who, like him, is in his fifties. The grinning surfers find their footing and shoot off into the distance, quickly dwindling into tiny specks.

Tanker surfing is said to have started locally in the ’60s, when a small group of fisherman and sailors started riding the waves made by cargo and tanker ships along Galveston Bay’s Redfish Island and Atkinson Island. Today, James is a kind of godfather of the sport, though he’s a bit of a controversial figure, thanks to his appearance in seminal 2003 surfing documentary Step into Liquid.

“You wouldn’t believe the backlash and hate mail I got from Texas surfers,” he tells us after the boat picks him and Doug up. “They were all furious that I seemed to suggest that the only surfing in Texas is tanker surfing, which, of course, isn’t true at all. The filmmakers heard about it and interviewed me, and it all kind of exploded after that.”

The sport has had an exclusive, members-only vibe. James, who owns Galveston surf shop Strictly Hardcore and is a lifelong surfer, offers charter trips on the bay, but only to certain people. “You have to be an advanced longboarder,” he says. “I don’t take beginners, and you have to be able to swim really well.” During the summer, he hosts serious amateur and pro surfers from as far as Australia, New Zealand, Japan and Europe. “It’s now on every serious surfer’s bucket list,” he explains.

The Mims brothers definitely rise to the level. Surfing is in their blood: They’ve been doing it for nearly four decades, locally and abroad. (Doug captains the Sam Houston II tour boat for the Port of Houston, while Joe is a retired pilot who works with wounded soldiers, hosting deep-sea fishing excursions for veterans and first responders.)

The brothers have their own set of criteria for who they’ll go out with. “I’ve been surfing my whole life, but I can always learn new tricks when it comes to tanker surfing,” says Joe. “If you don’t know the bay, or have the right tools to watch the depth, your boat can run aground. But even if you do know the bay, like Doug and me, it’s great to have someone like James, who knows exactly where to put the boat for the best ride.”

Taking in every aspect of the tankers—their size, speed, cargo, shape, design and draft—James can predict how and where a tanker wave will break, just by sight. “Every aspect matters,” he explains. “It can be big, but slow, or fast but shaped in a way that the wave isn’t rideable. You can’t guess. You have to know the vessels.”

James takes charters from May through September or October, with the summer months his busiest season and calmer waters and less wind making for ideal conditions. He typically travels 100 miles per trip, traversing the bay multiple times. Today, with Joe at the helm, he’s enjoying the chance—rarer, these days—to get on the water himself.

James knows the bay so well, he’s nicknamed its various sections. There’s Kiddie Pool, an area popular with newer tanker surfers, as well as Mom’s zone, the “magical” place where he spread his mother’s ashes, which features consistently rideable waves but can be hazardous, as it’s shallow in places and harbors a dangerous oyster reef.

As the hours pass, the day, which started at 6 a.m., takes on an almost magical quality. There’s a short rainstorm, followed by a double rainbow. The men troll along, the only surfers in sight on the emerald-green water, waving to smaller ships as they tail the huge tankers. (For their part, the tanker crews seem to appreciate the sportsmen. They’ve even videoed James surfing and posted the results on YouTube.)

The boat approaches Mom’s area. “Indicator!” James suddenly yells. He points to a spot half a mile away, where the water line seems to bend—a “hump,” he calls it. “That’s gonna be a good wave,” he says as Joe throttles the engine. The prediction, of course, is dead-on.

As the group reaches the wave and James and Doug mount their boards, it becomes apparent that they’re not alone: A pod of at least a dozen dolphins—“the best surfers in the water,” says Doug—have beat them to the punch. Not shy in the least, they join the men, leaping alongside them.

After a few minutes, Doug drifts back to the boat. James, however, stays up, disappearing into a dot in the sunlight. Joe tracks him from the boat, and he finally paddles up, beaming like a lottery winner.

“Man,” he gasps, “It didn’t stop. What a wave! Mom never disappoints—I was talking to her the entire ride.” He climbs into the boat, collapsing in a mix of joy and fatigue, and takes a deep breath. “I may never have to surf again.”